Abstract: A method is disclosed which brings together a combination of special IN features and techniques to allow Centrex stations supported by a plurality of central office switching systems, each at different locations, to function from the customer's perspective as though they were served by a single central office switch. The key to Virtual Wide Area Centrex is a total separation of the telephone numbers seen and used by customers (Customer Number Address--CNA) from the telephone numbers used internally by the network for call routing purposes (Network Node Address--NNA), such that there are two separate and distinct numbering plan domains. A central database, interconnected with each of the Centrex switches, maintains the mapping between CNA and NNA. This database is called upon, as required, to do both forward and reverse translations--i.e., from CNAs to NNA and vice-versa. The net result is that CNAs identify people (e.g., a customer's specific employees and agents) whereas NNAs identify locations (e.g.

Abstract: A method is disclosed for processing call data among telephone switching offices and a remotely located database system, called an SCP (Services Control Point), such that one large monolithic application at the SCP is shared among a very large number of individual services.